1. Field of the Invention
The present embodiments relates to methods, systems, and programs for detecting wear of a consumable part in semiconductor manufacturing equipment.
2. Description of the Related Art
Plasma has long been employed to process substrates (e. g., wafers or flat panels) to form electronic products (e.g., integrated circuits or flat panel displays). Semiconductor wafers are typically placed in an etch chamber with a photoresist mask layer to direct the etch of the underlying materials. The etching process removes the underlying materials not covered by the photoresist.
Etch systems have consumable parts in the chamber that wear off during the operation of the chamber. This requires periodic replacement of the consumable parts to maintain the on-wafer process performance according to specification, including CD (Critical Dimension) control, etch uniformity and defectivity. In a production environment, a single etch chamber may be used for multiple etch processes, each potentially having a different impact on the wear rate of chamber consumable parts. This makes it difficult to predict when a part will wear out and require maintenance, and if there is a known process adjustment available to compensate for wear, it may be difficult to know when to make adjustments in real time.
Some system administrators base consumable part replacement on the number of chamber processing hours, number of wafers run, or out-of-specification wafer metrology data. However, time-based maintenance schedules may lead to premature replacement of chamber parts, as the system has to account for the worst-case process condition. Further, wafer-metrology-based maintenance or process adjustments may suffer from a delay in feedback response of several hours or several days, until post-etch metrology tests are completed, which exposes wafers to risk while the process fault is detected.
It is in this context that embodiments arise.